Apparatus for forming S-Z twisted strand units

Abstract

Apparatus is disclosed for forming S-Z twisted strand units which comprises a frame and an elongated body mounted to the frame for rotation about a longitudinal body axis. The body is comprised of an assembly of tubules extending side by side longitudinally between opposite body ends. A first twisting head is rigidly mounted to one end of the elongated body which has a sheave mounted for rotary movement about a sheave axis transversing the longitudinal body axis. A second twisting head is rigidly mounted to the other end of the body having another sheave mounted for rotary movement about another sheave axis which transverses the longitudinal body axis. Means are also provided for rotating the elongated body in alternate directions about the longitudinal body axis. So constructed, strand units may be passed a plurality of times through the elongated body by routing the strand units through the body between the first and second twisting heads successively through the body without coming into contact with one another, and the body with its assembly of rotated in alternate directions thereby forming the strands into S-Z twisted strand units.

What is claimed is: 
     
       1. Apparatus for forming S-Z twisted strand units comprising a frame; an elongated body mounted to said frame for rotation about a longitudinal body axis and being comprised of an assembly of at least three tubules located radially about said body axis extending side by side longitudinally between opposite body ends; a first strands twisting head rigidly mounted to one end of said elongated body and a second strands twisting head rigidly mounted to the other end of said elongated body with each of said strands twisting heads having a plurality of sheaves each provided with an annular groove; and wherein the sheaves of each twisting head are mounted for rotary movement about mutual parallel axes with each sheave being aligned to receive strands extending linearily through a different one of said tubules with the groove of at least one sheave of each twisting head being partially offset axially from the groove of an adjacent sheave; and means for rotating said elongated body and said first and second strands twisting heads about said longitudinal body axis whereby strand units may be passed a plurality of times through the elongated body by routing the strand units through the body between the first and second twisting heads successively through the tubules without strand units moving in opposite directions through the body coming into contact with one another or with the body ends, and the body with its assembly of tubules rotated about the longitudinal body axis thereby forming the strands into S-Z twisted strand units. 
     
     
       2. Apparatus for forming S-Z twisted strand units in accordance with claim 1 wherein said sheaves of said first twisting head are mounted for rotary movement about mutually parallel first axes, and wherein said sheaves of said second twisting head are mounted for rotary movement about mutually parallel second axes. 
     
     
       3. Apparatus for forming S-Z twisted strand units in accordance with claim 1 wherein said elongated body is cylindrical and wherein said tubules are located along equally spaced radials of said cylindrical body about said cylindrical body axis, whereby upon rotation of said cylindrical body said tubules revolve about said cylindrical body axis. 
     
     
       4. Apparatus for forming S-Z twisted strand units comprising a frame; an elongated tube mounted to said frame for rotation about a longitudinal tube axis with the tube defining at least three channels extending between the tube ends; a first twisting head rigidly mounted to one end of said tube having a plurality of sheaves mounted for rotation about first mutually parallel sheave axes transversing said longitudinal tube axis; a second twisting head rigidly mounted to the other end of said tube having a plurality of sheaves mounted for rotation about second mutually parallel sheave axes transversing said longitudinal tube axis radially offset from said first sheave axes; and means for rotating said tube about said longitudinal tube axis; whereby strand units may be passed at least three times through the tube with strand units routed from one sheave of the first twisting head through one tube channel to one sheave of the second twisting head through a second tube channel to another sheave of the first twisting head and through a third tube channel to another sheave of the second twisting head and be formed into S-Z twisted strand units upon rotation of the tube without strands moving in opposite directions coming into contact with one another. 
     
     
       5. Apparatus for forming S-Z twisted strand units in accordance with claim 4 wherein said channels extend linearily through said tube closely adjacent said tube axis, and wherein each sheave of said first twisting head has an annular groove aligned with a mutually different one of said three linear channels, and wherein each sheave of said second twisting head has an annular groove aligned with a mutually different one of said three linear channels. 
     
     
       6. Apparatus for forming S-Z twisted strand units in accordance with claim 1 wherein the sheave axes of said first strands twisting head are nonparallel with the sheave axes of said second strands twisting head. 
     
     
       7. Apparatus for forming S-Z twisted strand units in accordance with claim 6 wherein said tubules number three and wherein the axes of said first and second twisting heads are mutually offset 120°.